Physics: Assembly of Bismuth Germanium Oxide (BGO) Crystal for the L-3 experiment at CERN. BGO (formula Bi4 Ge3 O12) is used to detect electrons and photons generated by electron- positron collisions in the LEP Collider ring. When an electron or photon enters the crystal, its energy is converted into light. The light is channeled by the crystal to photodiodes, producing an electronic signal. 11, 000 crystals, totaling 12 tons in weight, are used in the detector, measuring the energy and position of the incoming particles at very high resolution. The LEP and L- 3 detector were inaugurated on 13 November 1989. Geneva, Switzerland.